// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef GPU_COMMAND_BUFFER_SERVICE_FEATURE_INFO_H_
#define GPU_COMMAND_BUFFER_SERVICE_FEATURE_INFO_H_

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "gpu/command_buffer/service/gles2_cmd_decoder.h"
#include "gpu/command_buffer/service/gles2_cmd_validation.h"
#include "gpu/config/gpu_driver_bug_workaround_type.h"
#include "gpu/gpu_export.h"
#include <string>

namespace base {
class CommandLine;
}

namespace gfx {
struct GLVersionInfo;
}

namespace gpu {
namespace gles2 {

    // FeatureInfo records the features that are available for a ContextGroup.
    class GPU_EXPORT FeatureInfo : public base::RefCounted<FeatureInfo> {
    public:
        struct FeatureFlags {
            FeatureFlags();

            bool chromium_color_buffer_float_rgba;
            bool chromium_color_buffer_float_rgb;
            bool chromium_framebuffer_multisample;
            bool chromium_sync_query;
            // Use glBlitFramebuffer() and glRenderbufferStorageMultisample() with
            // GL_EXT_framebuffer_multisample-style semantics, since they are exposed
            // as core GL functions on this implementation.
            bool use_core_framebuffer_multisample;
            bool multisampled_render_to_texture;
            // Use the IMG GLenum values and functions rather than EXT.
            bool use_img_for_multisampled_render_to_texture;
            bool chromium_screen_space_antialiasing;
            bool oes_standard_derivatives;
            bool oes_egl_image_external;
            bool oes_depth24;
            bool oes_compressed_etc1_rgb8_texture;
            bool packed_depth24_stencil8;
            bool npot_ok;
            bool enable_texture_float_linear;
            bool enable_texture_half_float_linear;
            bool angle_translated_shader_source;
            bool angle_pack_reverse_row_order;
            bool arb_texture_rectangle;
            bool angle_instanced_arrays;
            bool occlusion_query_boolean;
            bool use_arb_occlusion_query2_for_occlusion_query_boolean;
            bool use_arb_occlusion_query_for_occlusion_query_boolean;
            bool native_vertex_array_object;
            bool ext_texture_format_astc;
            bool ext_texture_format_atc;
            bool ext_texture_format_bgra8888;
            bool ext_texture_format_dxt1;
            bool ext_texture_format_dxt5;
            bool enable_shader_name_hashing;
            bool enable_samplers;
            bool ext_draw_buffers;
            bool nv_draw_buffers;
            bool ext_frag_depth;
            bool ext_shader_texture_lod;
            bool use_async_readpixels;
            bool map_buffer_range;
            bool ext_discard_framebuffer;
            bool angle_depth_texture;
            bool is_swiftshader;
            bool angle_texture_usage;
            bool ext_texture_storage;
            bool chromium_path_rendering;
            bool blend_equation_advanced;
            bool blend_equation_advanced_coherent;
            bool ext_texture_rg;
            bool chromium_image_ycbcr_422;
            bool enable_subscribe_uniform;
            bool emulate_primitive_restart_fixed_index;
            bool ext_render_buffer_format_bgra8888;
        };

        struct Workarounds {
            Workarounds();

#define GPU_OP(type, name) bool name;
            GPU_DRIVER_BUG_WORKAROUNDS(GPU_OP)
#undef GPU_OP

            // Note: 0 here means use driver limit.
            GLint max_texture_size;
            GLint max_cube_map_texture_size;
            GLint max_fragment_uniform_vectors;
            GLint max_varying_vectors;
            GLint max_vertex_uniform_vectors;
            GLint max_copy_texture_chromium_size;
        };

        // Constructor with workarounds taken from the current process's CommandLine
        FeatureInfo();

        // Constructor with workarounds taken from |command_line|
        FeatureInfo(const base::CommandLine& command_line);

        // Initializes the feature information. Needs a current GL context.
        bool Initialize(ContextType context_type,
            const DisallowedFeatures& disallowed_features);

        // Helper that defaults to no disallowed features and a GLES2 context.
        bool InitializeForTesting();

        const Validators* validators() const
        {
            return &validators_;
        }

        ContextType context_type() const { return context_type_; }

        const std::string& extensions() const
        {
            return extensions_;
        }

        const FeatureFlags& feature_flags() const
        {
            return feature_flags_;
        }

        const Workarounds& workarounds() const
        {
            return workarounds_;
        }

        const gfx::GLVersionInfo& gl_version_info() const
        {
            DCHECK(gl_version_info_.get());
            return *(gl_version_info_.get());
        }

        bool IsES3Capable() const;
        void EnableES3Validators();

        bool IsES3Enabled() const
        {
            return unsafe_es3_apis_enabled_;
        }

        bool disable_shader_translator() const { return disable_shader_translator_; }

        bool IsWebGLContext() const;

    private:
        friend class base::RefCounted<FeatureInfo>;
        friend class BufferManagerClientSideArraysTest;

        ~FeatureInfo();

        void AddExtensionString(const char* s);
        void InitializeBasicState(const base::CommandLine* command_line);
        void InitializeFeatures();

        Validators validators_;

        DisallowedFeatures disallowed_features_;

        ContextType context_type_;

        // The extensions string returned by glGetString(GL_EXTENSIONS);
        std::string extensions_;

        // Flags for some features
        FeatureFlags feature_flags_;

        // Flags for Workarounds.
        Workarounds workarounds_;

        // Whether the command line switch kEnableUnsafeES3APIs is passed in.
        bool enable_unsafe_es3_apis_switch_;

        bool unsafe_es3_apis_enabled_;

        // Whether the command line switch kEnableGLPathRendering is passed in.
        bool enable_gl_path_rendering_switch_;

        bool disable_shader_translator_;
        scoped_ptr<gfx::GLVersionInfo> gl_version_info_;

        DISALLOW_COPY_AND_ASSIGN(FeatureInfo);
    };

} // namespace gles2
} // namespace gpu

#endif // GPU_COMMAND_BUFFER_SERVICE_FEATURE_INFO_H_
